PROJECT SUMMARY/ABSTRACT The Camp fire in November 2018 decimated the towns of Paradise and Magalia, California, burning nearly 14,000 homes but leaving about 1,700 homes in the area intact. Returning residents are now facing an unexpected threat ? benzene contamination in the drinking water. The measured concentrations in the public water distribution system are high, but spotty. Levels range from non-detect to 923 parts per billion (ppb), with 36% of the samples collected by the Paradise water utility so far showing benzene above the Maximum Contaminant Level (MCL) of 1 ppb. No systematic testing has yet been done inside the homes, and residents are returning to occupy homes that did not burn, creating an urgent environmental health situation. A similar problem was reported once previously, a year ago in Santa Rosa after the Tubbs fire, affecting only 13 homes. No research investigations have been conducted previously on this issue. This study is designed to answer the following questions: (1) What are the benzene and other volatile organic compounds (VOC) concentrations inside homes? (2) Are there other contaminants, whether regulated or non-regulated, in the water system? and (3) Are there clues to the source of the contamination? We will collect samples from 10% of homes (approximately 175 homes) in the fire-affected area, including some comparison samples outside the immediate fire zone. After initial analyses for VOCs, up to 20 homes with elevated concentrations will be selected to undergo intensive sampling, including multiple samples over time, different locations throughout the home, and sampling at the service connection. In addition to VOCs, these samples will be analyzed for additional contaminants using innovative non-targeted analyses. In this same subset of homes, we will conduct air monitoring for benzene and other VOCs. We will provide individual results to participating individuals and summary results to the community. This project will allow incorporation of information on potential drinking water exposures into ongoing research by the U.C. Davis Environmental Health Sciences Center on air and ash contaminants, and health data from fire victims. This work will be done in conjunction and collaboration with local agencies and community efforts to address immediate concerns about unexpected exposures and health. It will also serve as a foundation for preventing such exposures in the aftermath of future wild fires.